Can state-sponsored industrial espionage promote innovation and lead to self-sustained growth? I study the effect of 18th-century French industrial espionage on French innovation and industrial activity in the 19th century. Between 1730 and 1800 the French Bureau of Commerce promoted an ambitious plan aimed at stealing from Britain the new technologies of the Industrial Revolution, bribing British entrepreneurs and inventors to leave England and bring their expertise to France. I assemble a novel database with a comprehensive list of French espionage and combine it with newly digitized 17th- and 18th-century industrial surveys, 1800s industrial censuses, and the full list of early French patents. I find large, positive, and persistent effects of industrial espionage on industrial activity and innovation.